Cp*M(M=Co,Rh)and Ru(?)catalyzed Oxygen-directed C-H Bond Activation Amidation And Annulation

Transition-metal catalyzed C-H functionalizations became one of the most complementary and efficient bond-forming strategy over the past decades,most of these reaction occoured under mild reaction conditions with atom high economic efficiency,a wide range of substrates.However the majority of them require the use of noble tracnsition metals,such as Pd,Rh,Ir and Ru.It would be highly desirable for the development of these reaction catalyzed by the earth aboundant first-row TMs such as Co.In this context,the Cp*Co(III)and Ru(II)catalyzed amidation reaction to construct C-N bond and Cp*Rh(III)catalyzed cyclization reaction were studied.The main results obtained are shown as belows:(1)Cp*Co(III)-catalyzed Oxygen-directed C-H bond amidation of weakly coordinating sulfoxonium ylides and ?-benzoylketene dithioacetals have been realized.1,4,2-dioxazol-5-one as a amination,mild condition,high atomic economy and a wide range of substrates.The coupling system features high yields,broad substrate scope,and good functional group tolerance,providing a series of functionalized sulfur-containing compounds.(2)Ruthenium(II)-Catalyzed Oxygen-directed C-H bond amidation of Nitrones have been realized.Using N-alkoxyamides as an efficient electrophilic amidation regent,mild condition,arylnitrones functional group is well tolerated and the yield is high,and can be extended to a furan substituted substrate.The amination reagent has a good applicability for different substitution of the phenyl substrate,and can be extended to a substrate of an alkyl group and a heteroaromatic ring with high yield.(3)Cp*Rh(III)-catalyzed Oxygen-directed synthesis of nitro-functionalized indenes has been realized via C-H bond activation of arylnitrones and annulation with nitroolefins.The reaction proceeded in moderate to high yields with good functional group tolerance under ambient atmosphere.